A spectrum resource is a basis on which an operator operates a network, and rareness of the spectrum resource determines that a spectrum is a very precious resource. In addition, continuous development of mobile broadband and continuous evolution of 3G (third generation mobile telecommunications) and 4G (fourth generation mobile telecommunications) networks have resulted in an increasingly stronger demand of the operator for improving spectral efficiency. On this basis, in order to improve spectrum utilization, the operator proposes a Refarming (spectrum reallocation) technology. The Refarming refers to spectrum replanning, for example, generally refers to giving a section of a spectrum used by a low-standard system to a high-standard system for use, so as to improve the spectrum utilization without adding spectrum resources. Specifically, by using GL Refarming (GSM&LTE Refarming) as an example, GL Refarming refers to giving one section of a spectrum of GSM (Global System for Mobile Communication, Global System for Mobile Communications) to LTE (Long Term Evolution, Long Term Evolution) for use.
Specifically, during deployment of a GL Refarming solution, interference between the GSM system and the LTE system is a problem that needs to be solved first. At present, in this field, a GSM spectrum and an LTE spectrum are generally put at two ends of a spectrum respectively, or the interference between the GSM system and the LTE system is reduced by means of space isolation. That is, during deployment of the GL Refarming solution, in an area in which LTE has been deployed, GSM can use only a spectrum that is not occupied by LTE; otherwise, poor performance is caused by mutual co-channel interference between GSM and LTE; or a certain isolation distance is reserved geographically so that GSM can use the spectrum used by LTE.
For example, as shown in FIG. 1, assuming that an LTE site is deployed in area A and a frequency used by the LTE site is FB1, GSM can use only a frequency FB2 that is different from FB1 in area A. Correspondingly, in order to avoid the problem of co-channel interference between GSM and LTE, a certain co-channel isolation zone, for example, area B, can be reserved geographically, and GSM can also use only the frequency FB2 in area B serving as the co-channel isolation zone. Further, with protection of the co-channel isolation zone, GSM can use frequencies FB1 and FB2 in area C.
As can be seen from the foregoing content, at present, during deployment of the GL Refarming solution, LTE bandwidth that can be deployed needs to be limited by traffic load of the original GSM network. Because GSM has high traffic load in some areas and cannot give over more spectrums, only LTE with low bandwidth (for example, 5 MHz) can be deployed and throughput superiority brought by deployment of LTE with high bandwidth cannot be acquired; and an additional spectrum needs to be purchased if it is expected to deploy LTE with high bandwidth. Moreover, in the area in which LTE is deployed and the co-channel isolation zone around LTE, GSM can use only a frequency that is not used by LTE, thereby causing low spectrum utilization; due to a sharp reduction of spectrums available to GSM, loss of capacity and performance of the GSM network is caused.
In view of the foregoing problems, a corresponding LTE bandwidth compression solution is put forward in this field, that is, an LTE standard bandwidth is compressed by using an advanced filter technology and a scheduling algorithm. For example, 20M LTE standard bandwidth is compressed to 18 M by using a bandwidth compression technology, and the 2M spectrum obtained after the compression may be used for GSM deployment, so as to deploy LTE with relatively high bandwidth on an existing GSM spectrum under the premise of satisfying the capacity and the performance of the original GSM network.
However, because the spectrum compressed by using the bandwidth compression technology is very limited, in most scenarios, requirements of the original GSM network for the capacity and performance still cannot be met, and moreover, LTE with relatively high bandwidth cannot be deployed on an existing GSM spectrum, and an additional spectrum needs to be purchased if it is expected to deploy LTE with high bandwidth. Furthermore, in a same geographic area, GSM and LTE can only be deployed at adjacent frequencies, that is, either GSM or LTE uses a spectrum resource in a frequency domain; otherwise, severe co-channel interference is caused between GSM and LTE. Therefore, problems such as low spectrum utilization still exist.